A student's claim that a man pulled a gun on campus renewed anxiety one day after the FBI warned Philly schools of an unspecified threat, rumored to be a copycat warning based on last weekend's shooting in Oregon.

Reports that a college student had a gun pulled on him on a Philadelphia campus this morning did little to reassure a city on edge since the Federal Bureau of Investigation alerted area schools of a vague, possible threat on Monday.

However, the incident appears to be isolated and does not show an obvious connection to the previous warning.

A student at the Community College of Philadelphia told police that an acquaintance pulled a gun on him around 9:30 this morning, prompting a shelter-in-place while police searched for the suspect. Police have not said whether the suspect is also a student, but reported that the two men “have a history.” Neither was injured and police have taken the suspected gunman into custody.

The FBI did not cite a specific threat, but netizens tracked down an alarming message on 4chan, the same anonymous-user website where the Umpqua Community College shooter in Oregon is rumored to have posted a warning the day before the massacre last Thursday.

The first of our kind has struck fear into the hearts of America. His cries have been heard, even by the President…

On October 5, 2015 at 1:00 PM CT, a fellow robot will take up arms against a university in Philadelphia. His cries will be heard, his victims will cower in fear, and the strength of the Union will decay a little more...

The post closes by invoking “Hiro have mercy on us all. Lend us your strength to fight this evil.”

4chan has attracted criticism as a “bastion of cyber-pranksters” with “a long history of wreaking havoc,” in the words of ABC affiliate WPVI-TV.